TDI Hollis Prism II CCR Course

The Prism2 is a fully closed circuit Rebreather, ideal for exploring open ocean, cave, or wrecks. This unit can be electronically or manually controlled which means you choose how you want the loop PPo2 maintained.

Using the latest technology in CCRs can maximize your gas supply and provide an optimum breathing gas for any depth by maintaining a constant partial pressure of oxygen. It’s like having a nitrox blending machine on your back!

During this course, your TDI Instructor will teach you all of the necessary skills to conduct no decompression CCR dives to a maximum depth of 30 metres/100 feet using air diluent.

This course is for the certified diver looking to advance their diver level training and equipment configurations by learning to dive a rebreather. Whether you are an avid photographer, want to experience the silence of diving a rebreather, or looking to get closer to the marine life – rebreather diving is for you.

Note: Intro To Tech or remedial skills development may be required if the student is unable to demonstrate excellent bouyancy control and other basic skills.

Course prerequisites:

Minimum age 18

Provide proof of 20 logged open water dives

Provide proof as a TDI Nitrox Diver or equivalent from agencies recognized by TDI

What you can expect to learn:

The TDI CCR Air Diluent Diver course takes an in-depth look at all of the following and more:

History and evolution of rebreathers

Comparison of open circuit (OC), closed circuit, and semi-closed circuit, rebreather (SCR) systems noting the pros and cons of each

Some of the required skills you will have to demonstrate include all of the following and more:

All open water dives must be between 9 metres/30 feet and 30 metres/100 feet

Two dives must be deeper than 20 metres/50 feet and one dive must be deeper than 27 metres/90 feet

Partial pressure of oxygen not to exceed manufacturers recommendation or a working limit of 1.3

All dives to be completed within CNS percentage limits with a recommend maximum of 80 percent of the total CNS limit

Where the user opts for an automatic diluent valve (ADV) fitted and approved by the manufacturer, additional skills such as regular diluent gauge monitoring and addition control must be emphasized

Unit build up and break down

Predive checks

Verify diluent and oxygen contents using an analyzer

Demonstrate correct predive planning procedures

Cover emergency procedures

Use of BCD/dry suit and effective management of loop breathing volume for buoyancy control

Stop at 13-6 metres/ 10-20 feet on descent for leak/bubble check

Electronic system monitoring for partial pressure of oxygen levels (set point) and switching set points

Use of lift bag, or surface marker buoy and reel, where appropriate

Proper execution of the dive within all pre-determined limits

Demonstration of safety stops at pre-determined depths

Constant loop volume management

Post dive clean of unit

Diver maintenance of unit

What’s in it for you?

Upon successful completion of this course, graduates may engage in diving activities utilizing the CCR they were trained to dive without direct supervision of the TDI Instructor so long as the following limits are adhered to:

The diving activities approximate those of training

The areas of activities approximate those of training

Environmental conditions approximate those of training

To a maximum depth of 30 metres/100 feet

No decompression dives are permitted

TDI CCR Air Diluent Diver minimum requirements:

Satisfactorily complete the TDI CCR Air Diluent examination with a passing score of 80%, followed by 100% remediation by the Instructor

Complete a refresher course following a period of inactivity greater than 6 months following the course

Required Equipment:

The following equipment is required for each student:

Hollis Prism II CCR (can be rented for the course)

Bailout bottle (40 Cubit Foot minimum) and regulator set

Personal dive gear

Line cutting device

SMB

Reel or finger spool with at least 100' of line

Exposure suit adequate for the open water environment

Access to oxygen analyzer

How Much Does it Cost?

The TDI Hollis Prism II CCR Course costs $1500 per student. We schedule students together for group classes whenever possible unless a private class is specifically requested. Military and Public Service discounts are also available.

Note: Participation in the TDI Hollis Prism II CCR Class does not guarantee certification. Each student must complete the required number of dives, all the skills, and demonstrate that they are comfortable with planning and executing safe dives using Nitrox before they receive thier certification. If a student is unable to meet the course requirements additional training may be required.